Fair question. Here's an analogy which I hope will help.
The year is 2020. The Aztlan Party in Texas want to leave the United States. They are supported by 80% of the population of Texas, who snuck over the border during the McCain years.
I would expect the rest of America to be livid, and I would President Jeb Bush to send the national guard in. And if the Chinese bombed the White House to stop them, citing fictional-but-widely-reported atrocities that were reported happening in Texas, where a civil war had been raging between the immigrants and some heavily armed FReepers - I'd expect the Americans would be even angrier.
Remember that Kosovo is only 80% Albanian because Hitler introduced them en masse during WWII. They don't belong there.
So are you against the right of states to withdraw from the Union?
The conflict between the largely Christian (Eastern Orthodox) Serbs and the Muslim Albanians in this region has been going on for about a thousand years. It didn’t start with Hitler and WWII. I know some Serbs who are still bitter about the outcome of the Battle of Kosovo in 1389. Kosovo is claimed by most Serbs to be the ancestral home of Serbia. There is a cauldron of national, ethnic, and religious animosity there that boils over from time to time, aided and abetted by self-interested “allies.”
For Serbs KOSOVO = ALAMO !